1. Field of the Invention
The present invention relates to aerobic and anaerobic exercise equipment. More particularly, the invention concerns conditioning apparatus for shock-free exercising the user's legs and, in one embodiment, the full body, that is the upper and lower body simultaneously.
2. Discussion of the Invention
Walking and jogging have been traditional forms of aerobic exercise and weight lifting a traditional form of anaerobic exercise. The traditional form of weight lifting which requires barbells or complex machines with chains and weights, are not usually used for aerobic conditioning. In recent years, aerobic conditioning has become increasingly popular as evidenced by membership clubs providing supervised aerobic classes.
As jogging has become more popular the medical profession has noticed an increase of impact related injuries to the back, legs, feet and joints. To a lesser extent, regular walking has also contributed to these types of injuries. Those active in sports medicine generally agree that long-term jogging and walking, particularly on hard surfaces without proper equipment can result in serious debilitating injuries.
In addition to jogging and walking, which require relatively little expense for equipment, bicycling, tennis, handball, squash and similar sports are also a popular form of exercise particularly for the legs and lower body. Unfortunately, all of these sports can cause serious bodily injury if one is not careful. Furthermore, many of these sports require expensive special facilities and, if practiced in indoor facilities to avoid the uncertainties of the weather, become even more expensive.
Swimming is, of course, a well known and a popular form of full-body, shock-free exercise and is generally considered safer and far more beneficial than the above mentioned sports. Unfortunately, costly, special facilities are required and, in many parts of the country, private swimming pools are impractical due to weather considerations.
In an attempt to overcome the drawbacks of jogging, several manufacturers have produced elaborate types of treadmill-type aparatus. Such apparatuses basically exercise only the lower body and are typically quite expensive and often cumbersome, greasy and noisy to use. Maintenance costs for such equipment can be high and considerable space is often required for the equipment. Further, treadmill apparatus can be dangerous to use and injurious falls can occur with their use.
An example of a treadmill-like device with moving steps on a ramp is disclosed in U.S. Pat. No. 3,970,302, which also discloses an alternate device with pivotally mounted foot support members synchronized by a cable and pulley arrangement. Unfortunately, the exercising machines disclosed depend in part on chains, which are usually noisy and greasy, or cables or ropes which tend to become frayed and break. Frayed wire cables are particularly hazardous because of the potential to cut the user's hands, arms and legs. Cables and ropes also have the tendency to break thereby causing a sudden and often dangerous snap reaction to the user's body and limbs. Mechanisms using cables, ropes and chains generally have a certain amount of play when the mechanism is reversed thereby causing a jerky, bumpy or resistance-free movement especially at the beginning of the cycle when the direction of movement has been reversed. Since cables and ropes tend to stretch, mechanisms using them have an of undesirable amount of variation from one usage to the next. Furthermore, since cable and ropes do not support compressive loads, they can be dislodged from pulleys or damaged when the ropes or cables of such mechanisms are accidentally subjected to compressive loads. Examples of such machines are shown in U.S. Pat. Nos. 3,792,860 and 4,563,001.
The patented device of U.S. Pat. No. 4,563,001 uses a slot containing a cam follower to control movement of the levers. Unfortunately as the direction of motion of the levers is reversed at the end of each half cycle, play occurs between the slot and the cam follower. This play then becomes amplified at the ends of the foot and hand levers at the end of each half cycle as the direction of the motion is reversed.
One device which avoided the disadvantages of ropes, cables, and chains is disclosed in U.S. Pat. No. 4,600,187, which used a rocker plate which contained a pair of openings through which a corresponding pair of steps arms are loosely held or fitted. Because the steps arms must slide freely in the openings through which they pass, play is experienced at the end of each half cycle as the direction of motion is reversed. The sliding of the step arms in the openings tends to abrade or damage the step arms and openings thereby increasing the amount of play in the mechanism. Such abrasion together with the bending forces on the step arms at the point of slidable support at the opening tends to bend the step arms. When the step arms become bent, it can be appreciated that a major repair of the device is required. While these devices are useful, it is, nevertheless, well recognized that sports professionals highly favor exercise devices which provide a smooth and constant force to the user's body which is free of play, jerks or binding or sticking resistance in the devices moving parts.
Therefore, what is desired is an exercising machine which, will exercise the legs and lower body and without bumpy, jerky, or slack movement at the beginning of a cycle when the direction of motion of the mechanism is reversed. It would be especially desirable if the mechanism would like swimming, exercise the entire body. In any exercise machine it is also desirable that the device not have the disadvantages of the above mentioned sports such as high cost, weather dependency, and inducement of shock and unnecessary stress to the body. So that such an exercising machine can be enjoyed by many, it should be relatively inexpensive. So that it can be used by the apartment dweller, it should be a quiet and clean machine when used and not require weights or chains or components which require substantial amounts of grease for lubrication or wire cables or ropes which fray and break. Furthermore, it would be highly desirable if the exercising machine could be used both for aerobic or cardiovascular exercise as well as anaerobic or muscle building exercise to the extent desired by the user.
The apparatus of the present invention offers all of above mentioned advantages, requires a relatively small space so that it can be used and stored in the user's living room, and it is both relatively inexpensive to manufacture and maintain. In fact, the exercising machine of this invention is largely maintenance free.